The story is narrated by David Hayden, who is 52 at the time he is telling the story, but is only 12 when the events of the story occur. He recalls the summer of 1948 as the summer everything changed for him.
One day David notices that Marie Little Soldier, his Native American babysitter and house-keeper, whom he loves dearly, is sick with a cough. His parents, Gail and Wesley, agree to call Wesley’s brother Frank, who is a doctor. Marie protests, but they insist. When Frank is treating her, she is so upset and scared that Gail realizes something bigger is going on. After Frank leaves, Marie tells Gail that Frank has been sexually abusing women on the reservations who come to him seeking treatment.
Gail is furious, and tells Wesley what Frank has been doing. Wesley is the Mercer County Sheriff, but is also Frank’s brother, and doesn’t know how to proceed. He talks to Marie to get a clearer picture of her accusations. David realizes during this process that Wesley already knows his brother is guilty.
David and his parents have dinner a few nights later with Grandpa and Grandma Hayden. David hears Grandpa Hayden make jokes about Frank, who is his favorite son, liking “red meat.” Frank is there, and Wesley takes the opportunity to speak to him. David sees them talking, but can’t hear what they’re saying. At the end of the conversation, Frank shakes Wesley’s hand. On the way home, Wesley tells Gail that Frank has promised to stop the abuse. Gail says he needs to be punished for the crimes he has already committed.
The next day, Marie is found lying dead in her bed when Gail gets home from work. They are shocked, because Marie had been showing signs of improvement. That night, David tells his parents he saw Uncle Frank go into their house in the afternoon. He also says he believes their neighbor and Wesley’s deputy sheriff, Len McAuley, saw Frank as well. Wesley realizes his brother has probably killed Marie, and decides he must do something about it.
Wesley locks Frank up in the basement the next day, trying to spare him the embarrassment of being imprisoned in a jail cell. Grandpa Hayden comes to the house demanding Frank be released, and accusing Wesley of arresting him out of jealousy. Wesley tells his father that Frank is likely guilty of murder, and that he must face justice. After Grandpa Hayden leaves, Wesley tells David he should never let Grandpa or Grandma into the house if he’s home alone.
The following day, a truck circles the house. David recognizes some of Grandpa’s employees in the truck. They approach the house with an axe, presumably thinking they can break Frank out of the cellar door. Gail fires a shotgun at them as warning, and luckily Len shows up to head them off in time. Wesley comes home and asks what has happened. He realizes Grandpa Hayden has too much influence in this town, and that Frank will never be convicted. They all decide it is best to let Frank go.
But when Wesley talks to Frank, he realizes Frank is almost certainly guilty, and that he feels no remorse over killing Marie. Wesley cannot live with the idea of letting Frank go, and says he will take his brother to jail first thing in the morning.
That night David wakes up to the sound of shattering glass. He finds his parents awake. They tell him Frank is smashing preserve jars in the basement, for attention, and that no one should go downstairs. In the morning, however, when Wesley goes to wake Frank up, he finds him dead—Frank has slit his wrists with the broken glass. David believes that now everything can go back to normal, and feels grateful for his Uncle Frank’s decision.
Of course, things do not go back to normal. David’s family leaves Montana that winter. His father practices law in North Dakota, and David enjoys a relatively good life. He eventually becomes a history teacher, believing all histories contain concealed stories of abuse and depravity. He marries a woman named Betsy.
One night Betsy is having dinner with David and his parents, and she brings up the summer of 1948, remarking that Montana back then really was “the Wild West.” Wesley slams the table in anger, and tells Betsy she must never blame Montana. The novel ends with David sitting in his father’s seat at the table later that night—he believes he can still feel his father’s blow reverberating through the wood.